In a known bobbin holder of that kind (German laid-open application (DE-OS) No. 29 33 320), the tube plate member, beside the centering projection, has a flange which is provided with a plurality of catch notches. The edges of the catch notches are pointed to form a knife-like configuration. At the beginning of the winding operation, the thread which is to be wound on is fitted on a stationary thread guide which is disposed laterally of the bobbin frame, whereby the thread passes over one of the tube plate members. The thread then goes to a suction nozzle, from the stationary thread guide. When now the bobbin tube is caused to rotate by the friction roller, with the tube plate member also rotating therewith, the thread is engaged by one of the catch notches and is entrained over a part of the rotational movement of the tube plate member. If, as a result of that, the tension in the thread between the stationary thread guide and the tube plate member exceeds a certain value, the thread is to be cut off by the knife-like configuration of the edges of the catch notches. The cut-off end of the thread is then removed by the suction nozzle. Therefore, a necessary condition for that apparatus to operate at all is that there is a suction nozzle at each bobbin station. However, after the thread has been severed, the end of the thread which is on the tube or the tube plate member is not held with an adequate degree of certainty for it passes around the tube plate member or the tube only over a part of the periphery thereof. The fact that the thread does not extend around the tube or the tube plate member to a sufficient degree makes itself felt primarily when a large amount of thread has already been wound on the tube. As the leading end portion of the thread is not securely held on the tube plate member or the tube, it can come loose and it is therefore necessary to start the bobbin winding operation again. It may also happen that the thread is not severed by the knife-like configuration of the edges of the catch notches, as is the intention, but breaks due to the increased tension in the thread at some point between the suction nozzle and the tube plate member. In that case, the result is a thread end portion of greater length which projects beyond the tube plate member and which, upon rotational movement thereof, winds itself around the sleeve-like portion on the support arm. The coil of thread which is formed at that location then has to be removed again, by hand, which is an irksome operation.
The invention is based on the problem of providing a bobbin holer of the kind set forth in the opening part of this specification, which makes it possible for the thread to be substantially automatically and securely engaged, irrespective of the bobbin winding diameter, that is to say, when the tube or the bobbin is empty or has some thread wound around it, during the rotational movement of the bobbin in such a way that, when the bobbin is removed, there is also an adequate end portion of thread at the end of the bobbin, and that in addition thread is prevented from winding itself around the mounting means of the tube plate member.